Synthesis,Structures And Properties Of Metal-Organic Frameworks Based On Pillar[5]arene Ligands

Porous Metal-Organic Frameworks（MOFs）are polymers consisting of metal ions/clusters and organic linkers.Because of their structural diversity,high surface area as well as adjustable pore size and shape,MOFs have gained extensive research and industrial interest over the past decades and shown their great prospects in a wide variety of applications,including gas storage and separation,sensors,heterogeneous catalysis,fluorescence,biomedical fields and so on.This thesis is divided into three parts.The first part of this thesis studied the polycarboxylated pillar[5]arene-based MOFs.Two flexible pillararene ligands pillar[5]arene-modified tetracarboxylic acid ligand（H4L1）and pillar[5]arene-modified pyridine ligand（L2）respectively has been designed and synthesized.Compound 1 with one dimensional chain structure was synthesized by ligand H4L1 with zinc ion under solvothermal condition.Compound 2 and 3 were synthesized by H4L1 with cadmium ion under solvothermal condition and volatile conditions respectively.We investigated the dye adsorption of compound 2 with six different dye molecules that have different sizes and different charge.Compound 2 was able to selectively adsorb methylene blue（MB）which had matched size and charge.Because pillar[5]arene possessed of the rich electronic cavity,compound 2 was could be an ideal host for cationic guest.We investigated the host-guest interaction of compound 2 with six different guests.It was verified by NMR spectroscopy that compound 2 could interact with G1（adiponitrile）and G3（7,7’-（1,4-phenylenebis（oxy））diheptanenitrile）.The second part of this thesis studied the C3 symmetric hexacarboxylic acid-based MOFs.Compound 4-6 were synthesized by H6L3 with copper ion,zinc ion,cadmium ion under solvothermal condition respectively.These compounds were characterized by TGA,IR and PXRD.Since the porosity of compound 4 and 5 was more than 70%,the CO2 adsorption performance was studied emphatically.The fluorescence properties of compound 5 and 6 were also studied.The third part of this thesis studies the MOFs of Postsynthetic Modification（PSM）.PSM provides a new way to synthesize MOFs.PSM can incorporate many functional groups into the framework of MOFs,change the pore environment of MOFs,and improve the physical and chemical properties of MOFs.compound 5 was immersed in Cu²⁺ solution by metal ion exchange.PXRD,EDS,ICP-AES confirmed that Cue²⁺ was able to exchange Zn²⁺ in compound 5.